Diene trimerization



United States Patent 3,185,741 DIENE TRIMERIZATION f Ernest A. Zuech andWilliam G. Roberts, Bartlesville,

Okla, assignors to Phillips Petroleum Company, a corporation of DelawareNo Drawing. Filed Nov. 19, 1962, Ser. No. 238,747 12 Claims. (Cl.260-666) This invention relates to the trimeriz ation of dienes tocyclic 'aligomers. In one aspect theinvention relates to making cyclictrimers of conjugated aliphatic dienes. I -In another aspect theinvention relates to making 1,5,9-cyclo- .dodecatrienes by trimerizingbutadiene, pipe-rylene or isoprene in the presence of a catalyst formedby the admixtu're of titanium tetrachloride and diethylalurninumchloride and vanadium tetrachloride or vanadium oxytrichloride.

' Various methods have been disclosed for the trime-rization of dienesto cyclic a-ligomers. For example, US. Patent 2,964,574 of Gunther Wilkediscloses the production of trans, trans, cis-1,5,9-cyclododecatriene bytrimerizing butadiene in the presence of titanium tetrachloride anddialkylaluminum chloride. lyst-s are known .by which the cyclic trimersof other conjugated dienes such as isoprene and piperylene can beprepared. While some of these catalyst systems are suitable for theproduction of the desired cyclic trimers in high yields, in manyinstances the reaction rate is sufliciently slow that many hours ofreaction time are necessary to obtain the desired yields. 1

An object of this invention is to provide a new catalyst system forconverting conjugated dienes to cyclododeca trienes at a reaction ratesubstantially faster than previ ously known catalyst systems.

Another object of this invention is to provide an improved process tor.the production of cyclododec-atrienes from conjugated dienes.

Other aspects, objects and the advantages of my invention are apparentin the Written description and theclaims.

According to this invention, the trimerization of conjugated dienes tocyclododecatrienes is elfected at an increased rate by utilizing acatalyst system formed by admixing a 'dialkylaluminum halide, titaniumtetrachloride and a vanadium compound selected from the group consistingof -vanadium tetrachloride and vanadium oxytrichloride. Preferably, thedialkylaluminum halide is a dia-lkylaluminum chloride, apreferred-compound being diethylaluminum chloride. The invention isparticularly adapted to the conversion of 1,3-butadiene to trans, trans,cis-1,5,9-cyclododecatriene but is also applicable to the conversion ofisoprene and piperylene to the correspondingtrimet-hylcyclododecatrienes. The process is carried out by contactingone of the specified dienes with the above-specified catalyst system ata temperature generally in the range of 0 to 75 C. The pressuremaintained in the reaction zone will usually be in the range fromatmospheric to 100 p.s.i. However, higher or lower pressures 1 can beemployed.

Some examples of dialkylaluminum halides which can be employed aredimethylaluminum bromide, diethylaluminum chloride, diethylaluminumiodide, di-n-propylaluminum bromide, diisopropylalurninum iodide,di-n-butylaluminum chloride, and diisobutylaluminumbromide.

In the catalyst system of this invention, formed by the admixture of adialkylaluminurn halide, titanium tetrachloride and a vanadium compoundselected from the group consisting of V01 and VOC-lg, the catalystcomponents are charged such that the Ti/ V mole ratio will generallyfall Within the range of from 1/1 to 6/1 and the Al/Ti mole ratio willgenerally fall Within the range of from 2/1 to 10/1.

Furthermore, in utilizing the catalyst system formed of three componentsto effect the trimerizat-ion of aliphatic conjugated dienes to1,5,9-cyclododecatrienes, it is undesirable to permit contact of thevanadium component and the dialkylaluminum halide component in theabsence of the titanium component. Thus, We prefer to charge either thevanadium component or the dila-kylaluminum halide component last. Themost preferred method of charging the catalyst components is to chargethe 'DiCL, and the vanadium components, and thereafter contact themixture of these components with the dialkylaluminum halide component.After the catalyst components have been contacted together as describedabove, the diene to be trimerized is then contacted with the catalyst. i

The process of this invention can be carried out in the presence orabsence of a diluent. If a diluent is employed, it is most convenient tohave the diluent in the reaction vesselprior to charging the catalystcomponents.

After the trimerization reaction has been completed, the1,5,9-cyc1-od-odecatrienes can be recovered from the reaction mixture bysuch methods as distillation. Unreacted Other processes and catadienereactant and diluent can be separated in such a distillation andrecycled to the trimerization reaction.

While the'process has been described with particular reference to abatch operation, it is to be understood that the reaction can be carriedout either batchwise or cong the like, and mixtures thereof. Any diluentwhich is inert with respect to the catalyst system and to the othermaterials in the reaction zone, including the reactant and reactionproducts, including the desired reaction product and other productseither intermediate or other final products,

can be used.

The invention is not limited to the use of pure diolefin startingmaterials. It is possible to use as starting materials mixtures whichcontain the desired diolefin. For example, dehydrogenation products ofbutane and butylene which contain butadiene can be utilizedsuccessfully. Of course, the starting material should not contain anymaterial which has a harmful effect on the catalyst activity. The butaneand butenes present in the above-referred-to dehydrogenation product arenot harmful to the catalyst.

The trimers' of isoprene and piperylene are bothtrimethylcyclododecatrienes. In the case of the i-soprene trirner, eachof the three methyl groups is attached to a carbon atom which isattached to another carbon atom by a double bond. The piperylenc trimerhas the methyl groups attached to carbon atoms which are attached toother carbon atoms by single bonds.

The advantages of using the new catalyst system of this invention, andthus obtaining the increased reaction'rate obtainable by the use of thissystem, are obvious to those skilled in this field. For example, in acommercial unit in which 1,3-buta-diene is trimerized tocyclododecatriene, the shorter reaction time necessary to obtain a givenyield of cyclododecatriene allows one to utilize smaller reactionvessels, thus reducing the initial capital investment.

The following examples illustrate the operation and the advantages ofthe invention but are not intended to limit the invention to thespecific features illustrated in the runs.

EXAMPLE I A series of runs was carried out in Which 1,3-butadiene wastrimerized to trans, trans, cis-1,5,9-cyclododecatrione in the presenceof a catalyst system comprising diethylaluminum chloride. In someinstances the complete system comprised the diethylaluminum chlorideplus titanium tetrachloride; in others, diethylaluminum chloride Afterintroduction of the metal halides, 16 millimols of diethylaluminumchloride is charged to said zone. Isoprene is then charged dropwise tosaid reaction zone, and

plus either vanadium tetrachloride or vanadium oxytri- 5 cooling issupplied to hold the temperature oi the reacchloride; while in others athree-component system comtion medium below 75 C. A rapld conversion ofisoprising diethylaluminum chloride, titanium tetrachloride, prene to1,5,9-trimethyl-1,5,9-cyclododecatriene is oband one of the namedvanadium compounds were used. tained. The rate of trimerization is muchfaster in thls As shown in the tabulated data below (Table I), thetrirun than in a similar run when VCL, is omitted from the merization iseffected at a much faster rate when both catalyst system. the vanadiumand titanium salts are used in conjunction A LE 111 with diethylaluminumchloride than when either one is employed alone. In a run carried out bythe process of this invention In each run of this series, 50 ml. ofbenzene was piperylene is trimerized totrimethyl-1,5,9-cyc1ododecatricharged to either a 7-ounce (Runs 7, 8, 9)or 12-ounce 15 ene. Inthis run, 50 ml. of cyclohexane is charged toareac- (Runs 1-6) beverage bottle, after which the catalyst comtion zoneafter which 1 millimol of VCL, and 6 millimols ponents were charged inthe desired order by means of of Ticlg are charged to the reaction zone.After introa syringe inserted through the rubber seal of theperfoduction of the metal halides, 6O millimols of diethylalu- 'ratedcrown cap sealing the bottle. Gaseous butadiene minum chloride ischarged to said zone. Piperylene is from a cylinder was then admitted tothe bottle through then charged dropwise to said reaction zone, andcooling is a syringe. The manifold line from the cylinder to thesupplied to hold the temperature of the reaction media bottle was leftattached so that, as the pressure in the below 75 C. A rapid conversionof piperylene to tribottle fell below that of the cylinder due tobutadiene methyl-1,5,9-cyclododecatriene is obtained. The rate ofpolymerization, additional butadiene was charged to keep trimerizationis much faster in this run than in a similar the system at equilibriumpressure. Throughout these run when VCI, is omitted from the catalystsystem. runs, the pressures in the beverage bottles generally rangedfrom 15 to 25 p.s.i.g. The butadiene was first EXAMPLE IV charged atroom temperature and the trimerization initiated at this temperature,but since no. temperature con- In another run carried out by the processof this inventrol was used, the bottles warmed up rapidly due to tion,100 ml. of isooctane is charged to a reaction zone, the exothermicreaction taking place. The maximum after which 1 millimol each of VOCland TiC1 are temperatures ranged up to but did not exceed about chargedto the reaction zone. After introduction of the 70 C. metal halide, 2millimols of diisobutylaluminum iodide The results of these runs aretabulated below as Table is charged to said zone. Butadiene is chargedto the reac- I. In Run 6 of Table I, for example, of the 161 grams tionzone from a cylinder by the method of Example I, of butadiene taken up,113 grams of trans, trans, cisand cooling is supplied to maintain thetemperature of the 1,5,9-cyclodecatriene, 2.4 grams of1,5-cyc1ooctadiene, reaction mixture at C. A rapid conversion of buta-O.3 gram of vinylcyclohexene and 12 grams of rubbery diene to trans,trans, cis-l,5,9-cyclododecatriene is obpolymer were recovered. In TableI, trans, trans, cis- 40 tained. Comparison of the reaction rate withthat of a 1,5,9-cyclododecatriene is identified as CDT. similar runexcluding VOC1 shows the advantage of the Table I Butadiene MillimolesMillimoles Millimoles Order of uptake in Percent of Run ElSzAlCl, TiCll,catalyst Vanadium Vanadium salt addition of Ti/V, Al/Ti, grams afterXYield butadiene No. catalyst comcomponent B salt catalyst comcatalystmol mol hours CDT uptake ponentA charged charged ponent 0 componentsratio ratio grams represented charged charged by CDT 16 4 71 16 None...4 adiene polymerized to tough 1e 3 1 1e 4 1 11s 16 4 1 143 16 4 1 161 163 1 16 4 1 16 2 16 2 2 By comparing Runs 1, 2, and 3, it can be seenthat the three-component catalyst system of this invention is snperiorto either of the possible two-component systems employing adialkylaluminum halide and one of the metal halide components.Comparison of Runs 4 and 5 with Runs 3 and 6 clearly shows that it isundesirable to per mit contact of the vanadium component and thedialkylaluminum halide component in the absence of the titaniumcomponent. Run 7 shows that VOCl can be used as the vanadium component,while Runs 8 and 9 show the advantages of the three-component system ata higher Al/Ti mol ratio.

EXAMPLE II to a reaction zone after which 1 millimol of VCL; and 4three-component system in that longer times are required for equivalentconversion using the two-component system.

EXAMPLE V In another run, 50 ml. of chlorobenzene and 25 ml. of benzeneare charged to a reaction zone, after which 1 millimol of VCL; and 6millimols of TiCl, are charged to-said zone. After introduction of themetal halides, 4O millimols of dimethylaluminum bromide is charged tothe reaction zone. Butadiene is then charged to the zone by the methodof Example I, and cooling is supplied to maintain the temperature of thereaction mixture at 0 C. The butadiene is converted to trans, trans,cis-1,5,9- cyclododecatriene at a faster rate than in a similar runomitting the VCL; from the catalyst system.

Reasonable variation and modification are possible within the scope ofthis invention which sets forth a new 5 catalyst system for thetrimerization of dienes to cyclododecatrienes and a process for thetrimerization of dienes to cyclododecatrienes.

We claim: 1. A process for the production of a 1,5,9-cyclododecatrienewhich comprises contacting a reactant compound selectedfrom the groupconsisting of 1,3-butadiene, isoprene and piperylene with a cataylstsystem formed by admixing titanium tetrachloride, a dialkylaluminumhalide and a vanadium compound selected from the group consisting ofvanadium tetrachloride and vanadium oxytrichloride.

2. The process of claim 1 wherein the mol ratio of titanium to vanadiumis in the range of 1/1 to 6/1 and the mol ratio of aluminum to titaniumis in the range of 2/1 to 10/1.

3. The process of claim 2 wherein the reaction is carried out at atemperature in the range of to 75 C.

4. The process of claim 3 wherein the reaction is carried out in aliquid diluent which is inert to said catalyst system and to saidreactant compound and reaction products present in the reaction zone.

5. A process for the production of a 1,5,9-cyclododecatriene whichcomprises the steps of:

admixing titanium tetrachloride and a vanadium compound selected fromthe group consisting of vanadium tetrachloride and vanadiumoxytrichloride;

admixing with the resulting system formed by admixture of said titaniumtetrachloride and said vanadium compound, a dialkylaluminum halide; and

contacting the resulting system formed by admixture of said titaniumtetrachloride, said vanadium compound and said dialkylaluminum halidewith a come pound selected from the group consisting of 1,3-butadiene,isoprene, and piperylene.

6. The process of claim 5 wherein the mol ratio of titanium to vanadiumis in the range of 1/1 to 6/1 and the mol ratio of aluminum to titaniumis in the range of 2/1 to 10/1.

7. The process of claim 6 wherein the reaction temperature is in therange of 0 to 75 C.

8. The process of claim 7 wherein the reaction is carried out in thepresence of a diluent which is inert to said catalyst system and to saidreactant compound and reaction products present in the reaction zone.

9. A process for the production of a 1,5,9-cyclododecatriene whichcomprises the steps of:

admixing titanium tetrachloride and a dialkylaluminum halide;

admixing with the resulting system formed by admixture of said titaniumtetrachloride and said dialkylaluminum halide a vanadium compoundselected from the group consisting of vanadium tetrachloride andvanadium oxytrichloride;

contacting the resulting system formed by admixture of said titaniumtetrachloride, said dialkylalurninum halide and said vanadium compoundwith a compound selected from the group consisting of 1,3- butadiene,isoprene and piperylene.

10. The process of claim 9 wherein the mol ratio of titanium to vanadiumis in the range of 1/1 to 6/1 and the mol ratio of aluminum to titaniumis in the range of 2/1 to 10/1.

11. The process of claim 10 wherein the reaction temperature ismaintained in the range of 0 to 75 C.

12. The process of claim 11 wherein the reaction is carried out in thepresence of a liquid diluent which is inert to said catalyst system andto said reactant compound and reaction products present in the reactionzone.

References Cited by the Examiner UNITED STATES PATENTS 2,964,574 12/Wilke 260-666 3,066,126 11/62 Porter et a1. 26094.3 3,068,306 12/62 Hayet al 260-68315 ALPHONSO D. SULLIVAN, Primary Examiner.

1. A PROCESS FOR THE PRODUCTION OF A 1,5,9-CYCLODODECATRIENE WHICHCOMPRISES CONTACTING A REACTANT COMPOUND SELECTED FROM THE GROUPCONSISTING OF 1,3-BUTADIENE, ISOPRENE AND PIPERYLENE WITH A CATAYLSTSYSTEM FORMED BY ADMIXING TITANIUM TETRACHLORIDE, A DIALKYLALUMINUMHALIDE AND A VANADIUM COMPOUND SELECTED FROM THE GROUP CONSISTING OFVANADIUM TETRACHLORIDE AND VANADIUM OXYTRICHLORIDE.